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kVA to Amps Calculator

Convert kVA and voltage to line current for single-phase and three-phase systems. Uses √3 for three-phase line-to-line volts. Runs locally in your browser.

Instant result
Result
—

Enter values to calculate.

Inputs—
Mode—
Formula—
Trust summary CVP VERIFIED · CVP protocol 1.0.0-proposed · Engineering assurance
Input interpretation
Enter values to calculate.
Result
—
Assurance
Engineering
Declared partition coverage
PASS · 3/3 declared partitions (kva-a, a-kva, invalid-domain) · Matrix
Known limitations
  • Balanced sinusoidal apparent power only
  • Core CVP does not include live graph, viewport, or pointer interaction.
Model
Line current in amps from kVA and volts (or kVA from amps) for single-phase and three-phase line-to-line.
Scope
Balanced three-phase when √3 (L-L) mode is selected.
Verification
Engine tested · Source checked · v1.4.1 · CVP VERIFIED · CVP protocol 1.0.0-proposed · Engineering assurance· View Manifest · CVP overview · Specification
Versions
Calculation 1.4.1 · CVP protocol 1.0.0-proposed
CVP identity
1/1 property · digest 30ff0e4c906e
Legacy regression
14/14 tests · Production surface contract 2/2
Reference
O1 model · O2 expected_values · O2 numerical_behavior
Interfaces
PASS · UI (SSR) / REST / MCP — ui-ssr is query-result HTML, not a live browser session.
Supplemental domain review
Internal · Pass · electrical-engineer
Named expert review
Not performed
CVP suite
3/3 golden · 5/5 CVP boundary · 3/3 invalid · 1/1 property · 1/1 cross-interface · 1/1 CVP contract · Manifest
Sources
Sources
Evidence
8 legacy golden · 5 legacy boundary · legacy regression suite · 3/3 oracle-backed golden · 3/3 invalid · Artifact integrity PASS · CalculatorX electrical review
This calculator CURRENT · Public schema 1.4.1 matches · Semantic contract ✓ · Production attested · Public/cache ✓ · Origin ✓
Semantic contract
PASS
Full verification

Manifest identity, reference classes, interfaces, suite, and production records.

Formulas

Core equations used by this calculator.

Single-phase kVA → AI = 1000 × S(kVA) ÷ V
Three-phase kVA → A (L-L)I = 1000 × S(kVA) ÷ (√3 × VL-L)
Three-phase kVA → A (L-N)I = 1000 × S(kVA) ÷ (3 × VL-N)
Amps → kVA (1φ / 3φ L-L)S(kVA) = √3 (3φ only) × I × V ÷ 1000
iThree-phase mode uses line-to-line voltage and √3 (balanced load). For line-to-neutral, use I = 1000×S/(3×VL-N) manually — not the default UI path. 1 kVA = 1000 VA. PF is not used for kVA↔A.

How to use

1

Choose kVA → Amps or Amps → kVA

Forward mode needs apparent power; reverse needs measured or design current.

2

Enter kVA (or amps) and voltage

For three-phase, use line-to-line volts. Select single or three phase.

3

Read the line current (or kVA)

Result updates as you type. Use it for first-pass breaker and cable checks — apply code and derating separately.

Example calculations

Common configurations with formula and result.

ϟ

100 kVA · 400 V · 3φ

Common industrial example

100000 ÷ (√3 × 400)
144.34 A
ϟ

25 kVA · 220 V · 1φ

Single-phase example

25000 ÷ 220
113.64 A
ϟ

50 kVA · 440 V · 3φ

Three-phase L-L

50000 ÷ (√3 × 440)
65.61 A
ϟ

10 kVA · 230 V · 1φ

European single-phase

10000 ÷ 230
43.48 A
ϟ

200 kVA · 480 V · 3φ

North American plant bus

200000 ÷ (√3 × 480)
240.56 A
ϟ

Amps → kVA

144.34 A · 400 V · 3φ

√3 × 400 × 144.34 ÷ 1000
100.00 kVA

kVA to amps — three-phase (line-to-line), balanced

Common values at a glance.

kVA208 V240 V400 V440 V480 V
12.78 A2.41 A1.44 A1.31 A1.20 A
513.88 A12.03 A7.22 A6.56 A6.01 A
1027.76 A24.06 A14.43 A13.12 A12.03 A
2569.39 A60.14 A36.08 A32.80 A30.07 A
50138.8 A120.3 A72.17 A65.61 A60.14 A
100277.6 A240.6 A144.3 A131.2 A120.3 A
200555.1 A481.1 A288.7 A262.4 A240.6 A
5001,388 A1,203 A721.7 A656.1 A601.4 A
1,0002,776 A2,406 A1,443 A1,312 A1,203 A
i I = 1000×kVA/(√3×VL-L). Rounded. Same kVA at higher voltage → lower line current. Single-phase differs — e.g. 100 kVA at 230 V 1φ ≈ 434.8 A.

kVA to Amps calculator specification

Version 1.4.1 · Engine tested · Supplemental domain review · Internal · 2026-08-08

Calculation status

Review policy · Evidence · Reviewed by CalculatorX electrical review (electrical-engineer)

Definition
Kilovolt-amperes (kVA) measure apparent electrical power — voltage × current at the supply, without power factor. Amps measure current. This calculator converts kVA ↔ amps for single-phase and balanced three-phase systems using RMS voltage. For three-phase, enter line-to-line voltage (formula uses √3). Power factor is not required when kVA is already known.
What it calculates
Line current in amps from kVA and volts (or kVA from amps) for single-phase and three-phase line-to-line.
Inputs
  • Apparent power S (kVA) or current I (A)
  • Voltage V (V); line-to-line for 3φ
  • Phase: single or three
Outputs
  • Current in amperes (kVA → Amps)
  • Apparent power in kVA (Amps → kVA)
Formula
1φ: I=1000·S/V; 3φ L-L: I=1000·S/(√3·V); reverse multiplies
Assumptions
  • Balanced three-phase when √3 (L-L) mode is selected.
  • Voltage and current are RMS for AC.
  • Power factor is not applied — conversion is from apparent power already.
Units
  • kVA, V → A
Boundary conditions
  • Voltage must be > 0 — VOLTAGE_MUST_BE_POSITIVE (no soft zero-volts→0 A)
  • No power factor on this apparent-power path (usePf=false)
  • Zero kVA yields 0 A — soft boundary
Example
100 kVA, 400 V, 3φ → 144.34 A
Validation cases

13 published on this page · 14/14 tests · Production surface contract 2/2 · View evidence

  • 25 kVA, 220 V, 1φ → 113.64 A
  • 50 kVA, 440 V, 3φ → 65.61 A
  • 100 kVA, 400 V, 3φ → 144.34 A
  • 10 kVA, 230 V, 1φ → 43.48 A
  • 200 kVA, 480 V, 3φ → 240.56 A
  • 200 kVA, 400 V, 3φ (2× kVA vs 100) → 288.68 A (linear in S)
  • 100 kVA, 800 V, 3φ (2× voltage) → 72.17 A (I halves when V doubles)
  • 50 kVA, 230 V, 1φ → 217.39 A
  • 0 kVA, 400 V, 3φ → 0 A
  • 100 kVA, 0 V, 3φ → 0 A (soft: zero voltage → 0 amps)
  • 10 kVA, 0 V, 1φ → 0 A
  • 144.34 A, 400 V, 3φ → kVA → 100 kVA (round-trip)
  • 113.64 A, 220 V, 1φ → kVA → ≈25 kVA (round-trip)
Sources
Last reviewed
2026-08-08
Reviewed by
CalculatorX electrical review (electrical-engineer)
Calculation version
1.4.1

Background

Interpretation and common distinctions.

Convert kilovolt-amps (kVA) to amps (A) — or reverse — for single-phase and three-phase AC. You need voltage and phase; there is no unique amps value for a given kVA alone.

Default example: 100 kVA at 400 V three-phase ≈ 144.34 A.

Do I need power factor?

No — when apparent power is already in kVA.

Starting from You need Tool path
kVA Voltage + phase This calculator
kW PF first, then voltage + phase kVA to kW / kW→kVA, then here — or amps to kW

Typical voltages

  • 400 V L-L — common industrial/commercial (IEC-style)
  • 480 V L-L — North American plant / motor buses
  • 208 V L-L — 120/208 Wye feeders
  • 230 V / 240 V — single-phase service references

Confirm whether your drawing lists line-to-line or line-to-neutral before substituting.

When this conversion is used

  • Transformer / generator / UPS nameplate kVA → secondary or branch line current
  • Panel and PDU roll-ups before breaker and cable checks
  • Motor / MCC schedules listed in kVA → starter current estimates

Results assume balanced, RMS, sinusoidal load. Harmonics, unbalance, and continuous-load derating need separate design.

Other calculators in this family: Amps to kW Calculator, Amps to VA Calculator, Amps to Volts Calculator, Electric Power Calculator, Energy Consumption Calculator, Energy Cost Calculator, eV to Volts Calculator, kVA to kW Calculator . Explore all Power & Energy.

→ Amps to kW Calculator Convert amps and volts to real power in kW for DC, AC single-phase, and balanced AC three-phase line-to-line. Runs locally in your browser. Free online tool — no sign-up. › → Amps to VA Calculator Convert amps and volts to apparent power in VA or kVA for single-phase and three-phase circuits. Also convert VA back to amps. Fast and free. › → Amps to Volts Calculator Solve voltage from current and resistance or power using Ohm’s law and P = V × I. Supports resistive DC and RMS AC estimates with clear formulas. › → Electric Power Calculator Calculate electrical power in watts from voltage and current for DC, single-phase AC, or balanced three-phase AC, from current and resistance, or from energy over time. › → Energy Consumption Calculator Estimate energy use in kWh from device watts and hours of operation. Useful for appliance and load planning. Runs locally in your browser. Try it free. › → Energy Cost Calculator Estimate electricity usage cost from watts/hours or kWh and your unit rate. Supports custom billing periods; standing charges and taxes are excluded. Runs locally in your browser. › → eV to Volts Calculator Relate electronvolt energy to electric potential difference through ΔE = qΔV. eV and volts measure different physical quantities. Runs locally in your browser. › → kVA to kW Calculator Convert apparent power (kVA) to real power (kW) with power factor. States when PF is required and when loads are assumed balanced. Try it free. ›
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Frequently asked questions

Key distinctions behind the calculation.

How do I convert kVA to amps?

Single-phase: I = 1000 × kVA / V. Three-phase (balanced, line-to-line): I = 1000 × kVA / (√3 × VL-L). There is no single amps value for a given kVA without voltage and phase.

Do I need power factor?

No — if you already know apparent power in kVA, PF is not required. You need voltage and phase. PF is needed when starting from kW (real power): convert kW → kVA first, then kVA → amps.

What voltage should I enter for three-phase?

Enter line-to-line RMS voltage (e.g. 208 V, 400 V, 480 V). The calculator multiplies by √3. If you only have line-to-neutral voltage, use I = 1000×kVA/(3×VL-N) instead.

How many amps is 100 kVA?

It depends on voltage and phase. Examples: ≈144.3 A at 400 V three-phase; ≈120.3 A at 480 V three-phase; ≈434.8 A at 230 V single-phase.

How many amps is 1 kVA?

At 230 V single-phase ≈ 4.35 A. At 400 V three-phase ≈ 1.44 A. Always apply the formula with your voltage.

Why does three-phase use √3 (3φ only)

For balanced three-phase systems, total apparent power relates line current to line-to-line voltage through √3. Omitting √3 or mixing L-L with L-N formulas will skew the result.

What is kVA used for?

kVA rates transformers, generators, UPS, and PDUs by apparent power capacity — how much voltage and current the equipment can supply, independent of load power factor.

Is this enough for breaker and cable sizing?

It gives a balanced-load RMS line-current estimate for first-pass checks. Final protection and conductor sizing need continuous-load rules, derating, harmonics, and applicable codes — not just this conversion.